Visual training projector



June 6, 1961 E. E. KROPP ET AL VISUAL TRAINING PROJECTOR 7 Sheets-Sheet1 Filed April 13, 1956 M N/M w m r a r n J0 M v 0 a F. F. 4 NE .m w w ee X 5 w w M r June 6, 1961 E. E. KROPP ET AL VISUAL TRAINING PROJECTOR 7Sheets-Sheet 2 Filed April 13, 1956 Mix 5 Noe/Wm v 44, WA

fat/e 465/17" June 6, 1961 E. E. KROPP ET AL 2,986,968

VISUAL TRAINING PROJECTOR 1nd Aprll 13, 1956 7 Sheets-Sheet 5 June 6,1961 E. E. KROPP ET Al.

VISUAL TRAINING PROJECTOR 7 Sheets-Sheet 4 Filed April 13, 1956 Z sp WMMZ W m2 E &5 a 2 MMm w 1% M June 1961 E. E. KROPP ET A. 2,986,968

VISUAL TRAINING PROJECTOR Filed April 13, 1956 7 Sheets-Sheet 5 f V 1/93 a 66 75 10/ M -l F/a l0 f/wf/vrazs 52/6 .4. (ear/ June 6, 1961 E, E.KROPP ET Al. 2,986,968

VISUAL TRAINING PROJECTOR Filed April 15, 1956 7 Sheets-Sheet 6 '7Sheets-Sheet 7 Filed April 15, 1956 Q Z HN :MWZ r .we w N mp VENE A k a3 fig W mw k United States Patent 2,986,968 VISUAL TRAINING PROJECTOREric E. Kropp, Vinita Park, Vernon D. Gillham, St. Louis, and Max E.Norman, Normandy, Mo., assignors, by mesne assignments, to White-RodgersCompany, a corporation of Delaware Filed Apr. 13, 1956, Ser. No. 578,0349 Claims. (Cl. 88-28) This invention relates to visual trainingapparatus, and particularly to a film projector for projectingintelligible matter upon a viewing screen in a manner to develop speedand acuity of visual perception. The invention is an improvement of thedevices of this kind shown and described in the commonly assigned,copending applications of Louis J. Stoyanotf, Serial No. 227,771, filedMay 23, 1951, now Patent No. 2,775,827, and Serial No. 511,997, filedMay 31, 1953, and now abandoned.

These earlier applications disclose a visual training projector arrangedto present a pair of film strips in overlapping relationship before aprojector lamp for unison projection upon a viewing screen. One of thefilm strips, being referred to as the text film, consists of successiveframes upon which intelligible matter is photographed, and the otherfilm strip, being referred to as the fixation film, consists ofsuccessive frames which may be, alternately, wholly opaque and whollytransparent, whereby timed, momentary projection of a frame of text inthe projection aperture is achieved by feeding the overlapping fixationfilm strip through a transparent frame at a predetermined rate. Thefixation film strip may also consist of successive frames which arepartially opaque and partially transparent, with the ratio of theareasof the transparent and opaque portions being varied incrementallyfrom frame to frame so as to provide a stepped formation along the filmstrip, whereby successive portions of the matter on the text film aresequentially exhibited or masked to provided successive fixations forreading training as the fixation film is fed step by step through theprojection aperture with relation to the text film.

The film feeding means for these projectors include as prime movers, apair of solenoids, one for each film strip, which solenoids areenergized intermittently to 'operate through a forward and returnstroke, and each is arranged to drive, directly through sprocket orother means, one of the films one frame during a forward stroke.Selectivity of the frequency of this intermittent feeding motion isprovided for by a control system wherein the frequency of solenoidenergization is conveniently varied.

Problems in the reduction of noise level and impact stresses, and in theprecise indexing of the film, have arisen, however, in the use of thistype of intermittent feed mechanism, due to the considerable mass of thesolenoid plunger and its inherently abrupt acceleration and stopping.

The present invention has for its object the provision of a generallynew and improved visual training projector, employing two film strips,which incorporates a novel, variable rate, intermittent motion, filmfeeding mechanism which overcomes these problems, and which includesprovisions by which either of the film strips may be independently fedframe by frame under manual control, or repetitively at a selected rate,or by which both films may be fed concurrently at differential rateswhich have a predetermined fixed relationship.

More specifically, it is an object to provide an intermittent motionfilm feeding mechanism having a normally free-running, reciprocating,film engaging element cycling at a constant rate, and havingpredetermined acceleration and deceleration rates for itsfeedingand'return stroke, and including means for effecting an operativedriving connection between the mechanism and the film, either constantlyfor feeding at the constant driven rate or intermittently at selectedfrequencies, which frequencies are less than the constant driven rate ofthe feed mechanism thereby to effect variable rates of intermittent filmfeeding up to the constant driven rate of the feeding mechanism.

A further object is the provision of a two-film strip, reading trainingprojector having a pair of normally freerunning, intermittent motion,film feed elements driven at a constant rate, and separate electricallyoperated means for independently connecting each of the elements with afilm strip intermittently at selected intervals to drive thefilm oneframe, and having a control system including a film position sensitiveswitching means for effecting the feeding of one film strip one frameeach time the other film has been fed a predetermined number of frames.

A further object is the provision of a generally new and improvedcontrol system for repetitively energizing either or both of theelectrically operated connecting means at a preselected frequency.

These and other objects and advantages will appear from the followingdescription when read in connection with the accompanying drawings.

In the drawings:

FIG. 1 is a side elevational view of a visual training projector withits attached remote control unit constructed in accordance with thepresent invention;

FIG. 2 is an end elevation of the projector shown in FIG. 1;

FIG. 3 is an enlarged plan view of the remote control unit;

FIG. 4 is an enlared side elevational view of the remote control unit;

FIG. 5 is a top plan view of the projector with the cover portion of thecasing removed;

FIG. 6 is a side elevationalview of the projector with the casing coverremoved and with other portions sectionalized for clearer illustration;

FIG. 7 is a front end elevational view of the projector with the casingand other portions sectionalized for clearer illustration;

FIG. 8 is a bottom plan view of the structural cover member of the lowercasing portion and is taken on line 8-8 of FIG. 6;

FIG. 9 is an enlarged sectional view taken through the structural covermember and is taken along 9-9 of FIG. 6;

FIG. 10 is a sectional view taken on line 10-10 of FIG. 9;

FIG. 11 is a sectional view taken on line 11-11 of FIG. 9;

FIG. 12 is an enlarged detail portion of FIG. 11 showing one of the filmposition switches;

FIG. 13 is a sectional view of the film position switch taken on line13-13 of FIG. 12;

FIG. 14 is an enlarged detail View taken on line 14-14 of Fig. 9,showing the pivotal mounting of the claw arm;

FIG. l-S is a part sectional'view taken on line 15-15 of FIG. 14;

FIGS. 16 and 17 are end and side views, respectively, of one of the facecams;

FIGS. 18 and 19 are end and side views, respectively, of one of theradial cams;

FIG. 20 is an enlarged detail view of one of the solenoid actuatedswitches;

FIG. 21 is an enlarged detail view of one of the'cam actuated,synchronizing switches and is taken along line 21-21 of FIG. 6;

FIG. 22is a sectional view taken through 'thecenter 3 of the film gateshowing the cooling air passages and is taken along line 22-22 of FIG.9;

FIG. 23 is an outside elevational view of one of the film gates;

FIG. 24 is a sectional line 2424 of FIG. 23;

FIG. 25 is a sectional view taken on line 25-25 of FIG. 9;

FIG. 26 shows fragmentary portions of a typical text film and fixationfilm combination used in reading training;

FIG. 27 shows a fragmentary portion of a typical film strip used intachistoscopic training, and

FIG. 28 is a diagrammatic viewof the electronic control system.

Referring to the drawings in more detail, support structure is providedconsisting of an open box frame having upper and lower horizontal anglemembers 10 and 11, respectively, and vertical angle members 12, and aflat, rigid support plate 13 which is attached to the upper horizontalframe angles 10 by screws 14, see FIGS. 6 and 7. Enclosing the supportstructure is a lower casing section 15 and an upper cover casing section16 see FIGS. 1 and 2, which is detachably connected to the lower casingsection by luggage-type fasteners 17. The cover section 16 providesstorage space for the remote control unit 18 and its plug-in cord 19 andis provided with a carrying handle 20.

Mounted in the support frame, see FIGS. 6 and 7, is an electric motor 21having a shaft 22 on one end of which is keyed a V-grooved drive pulley23. The other end of motor shaft 22 carries keyed thereto an impeller 24which rotates in a volute housing 25 to supply a forced air draft. Thevolute housing 25 has an upwardly directed outlet 26 in which is mounteda projector lamp 27. Also mounted on the motor shaft 22, adjacent thepulley end and within the motorcasing, is a sliding vane-type rotor 28keyed to the motor shaft 22. The rotor 28 rotates in an eccentric stator29 and supplies compressed air through an outlet 30 and a flexibleconduit 31 for a purpose to be described. An aperture 32 is provided inthe support plate 13 through which the lamp 27 projects upwardly abovethe plate, and a lamp housing 33 having upper vents 34 encloses the lampand is attached to the support plate by screws 35. Cooling air suppliedby the impeller 24, passes upwardly around lamp 27, and out through theupper vents 34. Supported in the lamp housing is a conventionalreflector 36 and a condensing lens system 37, which may include theusual infra-red filter 38. A projector lens system 39 of conventionaldesign is mounted on the upper surface of plate 13 forward of the lamphousing, and is supported in a suitable cast support member 40 which, inturn, is attached to support plate 13 by screws 41.

A horizontal film guide assembly is mounted on the upper surface ofplate 13 between the lamp housing and projector lens. This assemblyincludes an elongated base member 42 which is attached to plate 13 byscrews 43, a double-faced film guide plate 44, and a pair of hinged filmgates 45, see FIGS. 9 and 22. The base member 42 has two pairs ofcentrally located, upstanding lugs 46 between which the film guide plate44 is inserted, and an upstanding lug 47 at each end thereof to whichthe ends of the guide plate are fastened by screws 48. The film gates 45are pivoted on pins 49, which are supported in ears 50 formed on a pairof cover plates 51. Each of the cover plates 51'spans a pair of lugs 46and forms therewith a vertical passage 52 extending upward from thesurface of support plate 13, see FIGS 9, 22, and 25.

The guide plate 44 has elongated, horizontal, film guide channels 53formed in its opposite faces, and each of the film gates 45 carries apressure plate 54 which enters its respective film guide channel toretain a film strip flat against the bottom of the channel when the filmgate is closed. The guide plate, the film gates, and the pressure plateshave projection apertures 55, 56 and ,57,

view of the film gate taken on 4 respectively, which are aligned withthe optical axis of the lens systems. Each of the pressure plates 54 isprovided with a vertical channel 58 in the outer face thereof alignedwith its aperture, and a transparent member 60 is mounted against theouter face of each pressure plate to enclose this channel, see FIGS. 23and 24, thereby to complete wide, fiat, vertical passages which formupward continuations of the passages 52, hereinbefore described, whenthe film gates are closed, see FIG. 22. Thus, when a film strip is inthe film guide groove and the film gate is closed, a continuous verticalpassage through the base member and pressure plate is provided, and thetwo opposite major wall areas of that portion of the passage extendingthrough the pressure plate are formed by the transparent member 60 onone side and the film strip on the other.

Cooling air, under pressure from the before-mentioned,

sliding,'vane-type air pump, is conducted to the under side of supportplate 13 through the flexible conduit'31 and through a suitable passage61 to the central portion of the base member 42, see FIG. 22. Thepressure plates 54 are carried on the film gates 45 by pins 62, whichare provided with heads at both ends, and which are freely slidable inapertures in the film gates and pressure plates. The pressure plates areresiliently held spaced from the film gates by springs 63.

The films are fed through the film guide channels in a frame by framemanner by two independently operable, variable rate, intermittent, feedmechanisms now to be described. Each of the feed mechanisms includes aclaw arm 64 which is pivoted at a point below the support plate 13 andextends upwardly through an elongated aperture 65 in support plate 13 toa free end adapted to engage its respective film. The claw arms 64 arearranged on-opposite sides of the film guide plate and are spaced onopposite sides of the projection aperture. The claw arms' each have anelongated lower hub portion 66. whereby they are mounted for freerotation in a plane perpendicular to the film guide and for free slidingmovement in a plane parallel to the film guide, one on each of a pair ofshafts 67 and 68, which shafts lie parallel to the film guide 44, seeFIG. 9.

The hub portions of the claw arms each include a double-row ball bearingin which the rows of balls are spaced sufiiciently to prevent twistingof the arms or rocking of the arms on their support shafts, see FIGS. 14and 15. The claw arms 64 are formed of flat stock and are arrangedflatwise with respect to the axes of their mounting pivots and the filmguide. At their upper free ends, the claw arms each carry a pair ofspaced claws 69, projecting perpendicularly from the flat sides thereof,which are adapted to enter perforations in a respective film strip. Theclaws on each arm are arranged in a spaced relationship which isparallel with the film guide, and the spacing may be equivalent to. thespacing of the film perforations, or it may be some multiple thereof.

Inasmuch as the film strips are quite thin and lie flat against thebottom of the film guide channel, horizontally elongated slots 70 areprovided in the film guide plate to permit entry of the claws 69, seeFIG. 12, so as to insure that they will enter the film perforationssufficiently to gain adequate purchase to pull the film in feeding.There would, otherwise, be a tendency of the claws, when entering theperforations, to bounce out if these slotted perforations in the filmguide plate were not provided. It will be seen that in order to permitfocusing of both films simultaneously, the space between them must bereduced to a practical minimum, that is, the guide plate in the filmchannel portion must be made as thin as is practical. This, then,presents a problem of interference between the claws of the claw armfeeding the film on one side of the guide plate and the film strip onthe other side.

In order to overcome this problem, the claw arms are spaced from. theprojection'aperture on opposite sides thereof, and the film gates andpressure plates are oppositely offset with respect to the projectionaperture, each in the direction of its respective claw arm. Referring toFIG. 5, it will be seen that due to this offsetting of the film gatesand pressure plates, the text film strip, indicated at 71, may beentered into the guide channel at an angle thereto in the direction offeeding (as indicated by arrows) so as to avoid interference with thefeeding claws on the opposite side of the film guide plate. This may beaccomplished by positioning the take-off spool, indicate at 72,laterally of the film guide plate sufficiently to insure clearance, asindicated, or in the case of the fixation film strip, indicated at 73,which may be a free-lying continuous loop as shown, the loop may bediverted slightly as by a guide pin 74 to insure that it approaches thefilm guide groove at an angle which will avoid the possibility of suchinterference.

Supported on the underside of the support plate 13, see FIGS. 8 and 10,is a pair of driving shafts 75 and 76 journalled at their outer ends inbosses 77 and 78, and journalled at their inner ends in bosses 79 and80, respectively. Shaft 75 has keyed to its outer end a V- groovedpulley 81, and the shaft is driven by motor shaft 22 through a belt 82over the pulleys 23 and 81. Shaft 76 is driven continuously at the samespeed as shaft 75 through meshed gears 83 keyed to shafts 75 and 76. Attheir inner ends shafts 75 and 76 each carry keyed thereto a radial cam84 and an adjacent face cam 85, each of which is loosely mounted on itsshaft. The face cams 85 are, however, each provided with a hub portion86 having splines 87 which slidably fit slots 88 in drive collars 89,which drive collars are keyed to the shafts thereby to effect rotationof the face cams with the shafts while at the same time permitting theirslight, free, axial movement on the shafts.

Underlying the driving shafts 75 and 76, and arranged perpendicularlythereto, are the rocking shafts 67 and 68 journalled at their outer endsin bosses 90 and 91, respectively, and at their inner ends in the bosses79 and 80, respectively, see FIGS. 9 and 10. These shafts 67 and 68besides forming pivot shafts for the claw arms 64 also each carry athrow-in yoke 92. These yokes each have a hub portion 93 which is keyedto its respective shaft, and each has a pair of upwardly extendingarcuate arms with roller elements 94 carried at the free ends thereof.These roller elements are arranged to engage the rear faces of the faceearns 85 so that, as shaft 67 or 68 is rotated in one direction, theface cam is shifted toward its adjacent radial cam and held there untilthe shaft is rotated oppositely.

The claw arms 64 are each provided with a follower button 95, theperiphery of which is arranged to be constantly engaged by a radial cam84 and the outer face of which is arranged to be engaged by a face cam85 when the face cam is moved in the direction of its adjacent radialcam by a throw-in yoke. Claw arms 64 are normally biased rotationallyoutwardly from the film guide by leaf springs 96, and are biasedinwardly, and axially of their pivot shafts, against the radial cams 84by coil springs 97. The claw arms are, therefore, reciprocated at aconstant rate axially of their pivot shafts and parallel to the films bythe radial earns 84. Each of the rocking shafts 67 and 68 is providedwith a crank 98 fixed thereon, which cranks are connected by connectingrods 99 to the plungers of solenoid actuators 100 and 101, havingwindings CLl and CL2 respectively. The arrangement is such that wheneither of the solenoids is energized it rocks its respective shaftthrough a crank 98 in a direction to cause the throw-in yoke 92 carriedthereton to move its respective face cam toward its adjacent radial camand against the face of the follower button 98 of its respective clawarm, thereby to render the face cam operative to move the claw arm intothe film perforations during a portion of its rotation. When thesolenoid is de-energized, the face cam merely floats axially on itsshaft and is inoperative to effect motion of the claw arm perpendicularto the film guide.

Each of the rocking shafts 67 and 68 also carry attached thereon neartheir outer ends an arm 102. These arms are arranged to each engage oneof the normally open, single-throw, double-pole switches S-11 and S-12,and to close it when its respective shaft is rotated upon energizationof its solenoid to move its face cam into operation. Suitable springreturn means (not shown) is provided in each of the solenoid actuatorsso that the rocking shafts 67 and 68 are rocked one way uponenergization and are returned oppositely upon de-energization. The clawarms 64 are provided with stop members 103 to limit their outward swingaway from the film guide. The constantly driven shafts 75 and 76 eachcarry a cam 104 which operates synchronizing switches S-7 and S-13respectively, the switches S-7 and S-13 being mounted on the under sideof support plate 13 adjacent the shafts 75 and 76, see FIGS. 8 and 21.These synchronizing switches have the function of synchronizing theenergization and de-energization of the solenoids with relation'to theangular positions of radial cams 84, and, therefore, with relation tothe positions of the claw arms in their forward and return stroke, sothat the film engaging claws do not ride on the film surface as they mayotherwise do if the solenoids were not synchronized to move the clawstoward the film only when they are substantially in a position to enterthe film perforations.

Each of the film gates carries a film position switch, designated as S-9for the fixation film gate and S-10 for the text film gate. Theseswitches consist of flexible contact brush elements 199 and 207,respectively, which ride on the surface of the film. The brushes aremounted in suitable insulating blocks as shown. When an aperture ornotch A-l in a moving film strip registers with a brush 199 or 207, thebrush contacts the metal surface of guide plate 44 to complete a circuitat that point. When the film gates are opened, these contact brushesbeing carried by the film gates are, of course, swung outward with thefilm gate so as to facilitate removal or insertion of film.

The control system diagrammatically shown in FIG. 28 is containedpartially in the remote control unit 20 and partially in the projectorcasing 15, the divided sections of the system being connected by theleads forming the cable 19. Referring to the diagram, a pair of supplylines 105 and 186 are provided for connection to a volt, single-phase,60 cycle power source. The closing of a line switch S-6, located in thelower left-hand corner of the diagram, completes a circuit for a relayRY7 which, upon closing its contacts 107, completes a circuit for theenergization of the driving motor 21 and projector lamp The circuit forrelay RY7 is traced from supply line 105, through fuse F-l, lead 108,switch S-6, lead 109, and through the winding of relay RY7 to line 106.The circuit for motor 21 is traced from line 105 through fuse F-2, relaycontacts 107, lead 110, motor 21, and lead 111 to supply line 106. Theprojector lamp 27 is connected across the motor circuit leads 110 and111 by leads 112 and 113.

The closing of line switch S-6 also completes a circuit for the primarywinding of a transformer T (top center of the diagram) which is tracedas follows; from supply line 106, through lead 112, a lead 113, theprimary winding of T, a lead 114, a lead 115, a lead 116 to lead 109,through switch S-6, lead 108, and fuse F-1 to supply line 185. Asecondary winding W-l of transformer T supplies 6.3 volts A.C. to thefilament 117 of a thyratron tube V-l through connecting leads 118 and119. A secondary winding W-2 of the transformer T supplies 6.3 voltsA.C. to energize a relay RY7 through a circuit which may selectivelyinclude either of the film position switches S-9 or S40, to be describedlater.

A source of D.C. supply is provided by selenium rectifiers SR1 and SR2connected across the A.C. supply. Recasset-see:

ttfier SR1, being connected to a first side of the primary oftransformer T through a current limiting resistor R-2 and the lead 114and to the other side through a capacitor C-1 and lead 113, rectifiesduring one half of a cycle to provide B+ at a point designated 120. SR2,being directly connected to the first side of transformer T throughleads 115 and 114 and connected to the other side through a capacitorC-2 and lead 113, rectifies during the other half of the cycle toprovide B at a point designated 121. Lead 113 which connects with supplyline 196 therefore becomes a common return for the DC. voltages. Due tothe alternate charging and discharging of capacitors C-1 and -2,- thevoltages at 120 and 121 are approximately +150 volts and -150 voltsrespectively.

'The thyratron tube V-1 has a control grid 122 on which a normallynegative bias is maintained through its connection to B at 121,which maybe traced as follows; from point 121, a lead 123, a lead 124, normallyclosed upper contacts 125 of-a relay RY3, a lead 126, a lead 127,normally closed contacts 128 of a relay RY4, a lead 129, normally closedupper contacts 130 of a double-throw, push-button switch 8-4, a lead131, normally closed upper contacts 132 of a double-blade, double-throw,push-button switch S-5, a lead 133, a resistor R-7, a lead 134, a lead135, parallel resistor and capacitor R-6 and C-6, and a lead 136 to grid122. The cathode 137 of tube V-l is connected to the common line 113through leads 138, 139, 140, and 141.

The control system and its operation will now be further described inconnection with its several film feeding functions.

When it is desired to feed the fixation film strip 73 one frame at atime under manual control, the function switch knob FS, shown on theremote control unit in FIG. 3, is turned to 'No. 1 position. This actionpositions all of the switches at the left-hand side of the controldiagram marked SlA, SIB, SIC, and SID in their No. l position. Themovable switch arms of these switches are mounted on a common shaftwhich is turned by the knob FS. Having positioned the function switch,the double-throw, push-button switch -4 is now depressed. Depressingswitch S-4 breaks the just-described connection between B- at 121 andgrid 122 through contacts 130 of 8-4 and removes the negative bias. Theclosing of lower contacts 142 of switch S-4 completes a circuit forenergization of a relay RYS. This circuit may be traced as follows: fromB- at point 121 through lead'123, lead 124, contacts 125 of RY3, lead126, lead 127, contacts 128 of RY4, lead 129, contact 142 of switch 8-4,a lead 143, a lead 144, a lead 145, upper contact 146 of RY4, a lead147, and through the winding of RYS to common lead 113. Energization ofRYS effects closing of its contacts 148 and permits the charging of acapacitor C-7 through a resistor R-9, which action applies a strongpositive pulse to the tube grid 122 through the synchronizing switch8-13 when it closes. The synchronizing switch 8-13 is arranged to closeand deliver this pulse at a time just prior to the completion of thereturn stroke of the claw arm so that the face cam will move the clawarm toward the film at a time when the claws at the free end of the armare in position to register and enter a pair of perforations in the filmstrip. This positive pulse may be traced as follows: from 3-1- at 120,through lead 143, lead 153, rightward through lead 152, resistor R-9,lead 151, capacitor C-7, contact 148 of RYS, lead 149, switch S-13, alead 150, a lead 208, aresistor R-7, leads 134 and 135, capacitor andresistor C-6 and R-6, and a lead 136 to grid 122.

With the negative bias on grid 122 broken at contact 130 of'switch S-4and the strong positive pulse applied thereto through C-7, the tube V-1conducts and energizes fixation film solenoid winding GL1. The platecircuit of tube V-1 extends from its plate 154 through lead 1'42,-;a'lead' 155 ,a lead- 156, position No. l of switch 510, a'lead:;57.,c0ntact 15.8.; of switch 5-5, .a ad.

solenoid winding CLl, a lead 160,-a' lead 161, resistor R-10, and a lead162 to B-]- at point 120. Energization of solenoid CLl causes the facecam 86 of the fixation film feed mechanism to be moved inward to effectthe feeding of thefixation film one frame. Energization of solenoid CLlalso effects the closing of contacts 163 and 164 of the solenoidactuated switch S-ll (located just below CL1), and this action energizesa relay RY6 through the following circuit; from one side of relaywinding RY6 through a lead 165, upper contact 163 of switch 8-11,through lead 144, a lead 143, through the now closed lower contact 142of switch 8-4, lead 129, contact 128 of RY4, lead 127, upward throughlead 126, contact of RY3, lead 124, and lead 123 to B- at 121. The otherside of winding RY6 is connected to common lead 113 through a lead 166.Upon energization of RY6, its lower contacts 167 close and complete aholding circuit around the solenoid actuated switch S-11 to maintainenergization of RY6 from lead 144, through a lead 168, contacts 167, thewinding of RY6, and lead 166 to common lead 113. Also, upon energizationof RY6, its upper set of contacts 169 close and complete a circuit tore-establish the negative bias on tube grid 122 to prevent the tube V-1from conducting again, once it has been cut off, so that the fixationfilm will be moved only one frame no matter how long push: button switch8-4 is held depressed. This negative bias is applied from B at point121, through leads 123 and 124, contacts 125, lead 126, contacts 169 ofRY6, lead 150, lead 208, resistor R-7, lead 134, resistor R-6 andcapacitor C-6, and lead 136 to grid 122. When the fixation film has beenfed one frame, the synchronizing switch S-7 closes and applies a strongnegative pulse to plate 154, through the discharge of a capacitor C-3,to cut off tube conduction. Before switch S-7 closes, and while the tubeis conducting, the capacitor C-3 is charged through a resistor R-3 andlead 143 to B+ at 120. The release of push-button switch S-4 opens thecontacts 142, dropping out relay RY6 and removing the negative grid biasthrough this relay, but it also again closes its contacts to establishthe normal negative bias through these contacts.

If it is desired to feed the text film one frame at a time under manualcontrol, the function knob is again placed in position No. 1. Apush-button switch 8-5 is now depressed. Depressing switch S-S causesits upper switch blade 132 to break with its upper contact, therebybreaking the normal negative bias, and causes blade 132 to make with itslower contact to effect the charging of (3-7 to deliver a positivepulseto grid 122 through the same circuit as before. When lower'switch blade158 of 8-4 breaks with its upper contact, it breaks the connectionbetween solenoid CLl and the tube plate and establishes through itslower contact the connection of the text film solenoid CL2 into the tubeplate circuit through the leads 170 and 171. Otherwise, operation is thesame as that in feeding the fixation film. Therefore, whenever S-4 ispressed, the fixation film will be fed one frame, and when 8-5 isdepressed, the text film will be fed one frame, and no matter how longthese buttons are held depressed, only one frame will be fed.

When it is desired to repetitively feed the fixation film a frame at atime at a selected rate, the function switches 81A to S1D are againplaced in position No. l. The depressing of a Start button on the remotecontrol unit closes contacts 172 of a starting switch 8-2 in the upperleft-hand portion of the diagram, which completes a circuit forenergization of relay RY4. This circuit extends from 13+ at point 120through lead 143, lead 153, lead 152, through the winding of relay RY4,through lead 173, upper contacts 174 of a relay RY2, a lead 175, switchSIB in position No. 1, through now closed starting switch S-2, andthrough a lead 176 to the common side of the DC. voltages at lead 113.The energization of relay RY.4.;in t rn com e e an e g zin v r t f rrelax RY3 through the normally open lower contacts 177 of RY4. Thiscircuit is traced from B+ at 120 through lead 143, lead 153, lead 178,the winding of RY3, a lead 179, contacts 177 of RY4, a lead 180, a lead181, contacts 182 of a Stop" switch 8-3, a lead 183, a lead 184,normally closed contacts 185 of relay RY1, a lead 186, switch 81A inposition No. 1, and lead 176 to the common lead 113.

The closing of relay RY4 also now completes through its upper normallyopen contact 187 an energizing circuit for relay RYS to place a positivepulse on grid 122, and this circuit is traced as follows; from B+ atpoint 120 through lead 143, lead 153, a lead 188, contact 187, lead 147,and through the winding of relay RYS to common lead 113. Opening of thenormally closed, middle contact 128 of RY4 upon energization alsointerrupts the normal negative bias on tube grid 122, and the closing ofits normally open middle contact 190 connects T8- at 121 with one of thecontacts 163 of solenoid actuated switches S-ll so that, when solenoidCLl is energized and switch S-11 closes, a circuit for energization ofrelay RY6 is completed. When relay RY3 is energized by the closing ofrelay RY4, its energization is maintained by a holding circuit extendingfrom B+ at 120 through lead 153, lead 178, the winding RY3, and throughits lower contacts 191, lead 181, contacts 182 of Stop switch 8-3, lead183, lead 184, contacts 185 of RY1, lead 186, switch S1A, and lead 176to common lead 113. The now closed middle set of normally open contacts192 of relay RY3 completes a circuit for the energization of relay RY2,and its upper normally closed contacts 125 open to break a connectionbetween B at 121 and contacts 169 of relay RY6.

The energizing circuit for relay RY2 completed by the closing ofcontacts 192 of RY3 extends from B+ at 120 through lead 143, lead 153,the winding of RY2, a lead 193, contacts 192 of RY3, and a lead 194 tocommon line 113. When relay RY2 is energized, it breaks with its uppercontact 174, thus breaking the circuit for relay RY4 which then dropsout. Under these conditions, with relay RY4 de-energized and relay RY3holding in, the control of the circuit is removed from Start switch S-2,which may now be released, and the only way in which RY3 can bede-energized is by opening of the Stop switch S-3 or the opening ofcontacts 185 of relay RY1.

When relay RYS is energized by the action of relay RY4, capacitor C-7charges, as before described, and a strong positive pulse is applied togrid 122 through the synchronizing switch S-13 when it closes. Thistogether with the fact that the normal negative bias on the grid wasinterrupted by relay RY4 causes the tube V-1 to conduct and energizesolenoid CLl through the beforedescribed plate circuit so as to effectthe feeding of the film.

When the solenoid CLl energizes, it closes contacts 164 of solenoidactuated switch S-11. This action applies a strong negative bias to grid122 from B- at 121 through leads 123, 195, contacts 164, leads 196, 134,and 135, capacitor C-6 and resistor R-6, and leads 136 and 137. Thisaction also effects the charging of a capacitor C- through a resistorR-5 and the lead 141 to the common lead 113. When feeding of the filmone frame has been effected, synchronizing switch S-7 closes, whereuponcapacitor C-3 discharges to provide a negative pulse to tube plate 154which, together with the negative bias applied to the grid, cuts offtube conduction.

Switches S-7 and 8-11 now reopen due to rotation of the synchronizingswitch cam and to de-energization of the solenoid, and the capacitor C-5now begins to charge from B- toward B+ voltage through lead 134, aresistor R-8, a lead 197, potentiometer P-l, lead 152, and lead 153 toB+ at 121 at a rate determined by P-l. The resistance P-l is varied byturning the speed control knob S-C on the remote control unit. When thegrid again becomes sutficiently positive, the tube will fire andsolefilm solenoid winding CM is directly connected into the 10 noid CLIwill again be energized to effect the feeding'of the film one frame.This repetitive action will continue at a selected rate determined bythe charging rate through speed control P'-1 until the energizingcircuit for relay RY3 is broken, either by opening of Stop switch S-3 orby opening of contacts of relay RY1.

When it is desired to automatically interrupt this repetitive feeding atone or more points along the film strip, perforations or notches areprovided in the film, as shown in FIG. 26, and a double-throw, selectorswitch S-14, shown in the upper left-hand corner of the diagram, isthrown to a position to close its contact 198. The registration of oneof the apertures or notches N-l in the film strip with the contact brush199 of fixation film position switch 8-9 will effect the completion ofan energizing circuit for relay RY1. This circuit is traced as follows;from one side of transformer secondary W-2 through a lead 200, contactbrush 199, a lead 201, contacts 198 of switch blade S-14, a lead 202,the winding of RY1, and a lead 203 to the other side of secondary W-2.Actually this circuit is completed through the film guide plate 44 andground when contact brush 199 enters a hole in the film and contacts thefilm guide plate, but for simplicity, leads are shown in the diagram.Energization of RY1 effects the opening of its contacts 185, whichbreaks the holding circuit of RY3 and stops operation. Repetitivefeeding is resumed by again depressing the Start switch S-2.

The provision of the film position switching means and spaced aperturesor notches in the film strip enables the operator to automatically feedthe precise desired number of frames without overrunning, which mayotherwise occur if he were to rely on manually pressing the stop button.

-When it is desired to feed the text film strip 71 repetitively frame byframe at a desired rate, the function switch is rotated to position No.3. This action places SIA and SID in position No. 3, which disconnectsthe fixation solenoid winding CLl from the tube plate circuit bybreaking contact at position No. l in SIC, and it connects the text filmsolenoid winding CLZ in the tube plate circuit through position No. 3 ofswitch SIC. In order to automatically interrupt feeding of the textfilm, the selector switch 8-14 is thrown over so that its contacts 198are open and its contacts 204 are closed. Under these conditions when anaperture or notch N-2 in the text film 71, shown in FIG. 27, registerswith contact brush 207 of the text film position switch 8-10, RY1 willbe energized through S-10 instead of 5-9. Otherwise, the operation isthe same as just described in connection with repetitively feeding thefixation film. Automatically interrupted repetitive feeding, as justdescribed, is particularly useful in a phase of visual training calledtachistoscopic training. In this training method, a frame of filmcontaining a configuration, phrase, or numeral is projected, as a whole,for a short, measured interval to develop rapid recognition. The filmstrip shown in FIG. 27 shows alternate blank and subject frames with thesubject repeated at least once. Also, there is shown on this stripnotches N-Z associated with each frame on which it is desired toautomatically interrupt the feeding.

In reading training, it is desirable to automatically feed the fixationfilm frame by frame repetitively until all of the matter on one frame ofa text film is exposed, and to then feed the text film one framesimultaneously with the next frame of the fixation film so thatsuccessive portions of the subject matter, from line to line on oneframe of text and from frame to frame of the text, is continuouslyexposed throughout the length of text which may extend over a pluralityof frames. In order to accomplish this, the function knob is turned toposition No. 2, and selector switch 5-14 is thrown to a position toclose with its contact 198.

With function switches in position No. 2, the fixation amass.

'11 tube plate circuit through-S16 as before. But, now, both CLl and thetext film solenoid winding CLZ will be connected into the tube platecircuit through the normally open contacts N of relay RY1 when it isenergized, and due to the position of selector switch 5-14, RY1 will beenergized when an aperture in the fixation film registers with thecontact brush 199 of fixation film position switch 8-9. This effects thefeeding of. both film strips one frame simultaneously upon theoccurrence of an aperture or notch N4 in the fixation film strip. Afterthey have both been fed this frame, the film notch has, of course, movedon past the contact brush 199 and feeding of the fixation film aloneagain continues. When the function switches are moved into position No.2, contact 2 of 81A completes a shunt to common lead 113 around contacts185 of relay RY1 so that, when relay RY1 is energized, the opening ofcontacts 185 will not break the holding circuit which maintainsenergize.- tion of RY3. Operation is stopped by depressing stop switchS-3.

In the repetitive feeding of either film strip at selected frequencies,the synchronization of tube firing with the position of the claw arm isaccomplished by a combination of decay time of the negative cut-offpulse through variable resistor P-1 and by the application of a triggerpulse applied to the grid network when synchronizing switch S-7 opens.This trigger pulse is applied through a capacitor 04 and resistor R-4 tothe grid network at (3-5. By way of example, let it be assumed that thetube fires at zero grid potential, that the cam of switch S-7 rotates attwenty-four revolutions per second and delivers a +50 volt pulse eachtime switch S7 opens, that the negative cut-off pulse applied uponmomentary closing of solenoid switch S-ll drives the grid to -l50 volts,and that it is desired to fire the tube and energize the solenoid twotimes per second, or every twelfth revolution of the switch cam. Underthese conditions variable resistor P-l would be set so that in one-halfsecond, the -150 volt negative cut-off pulse will decay to ,50 volts, orslightly less. Then, upon the next instance of opening of switch 8-7,the +50 volt pulse applied to the grid network through 04 and R4 willcause the tube to fire at that point in the rotation of the cam drivingshaft which, as before described, also reciprocates the claw arm.

When it is desired to feed the text film strip repetitively at themaximum rate, the function switch knob is turned to position No. 4. Thisconnects one side of text film solenoid winding GL2 to common lead 113through switch SID, the normally closed contacts 185 of RY1, and 51A.The other side of CLZ is connected to B-lat 12%. The circuit for GL2 istraced as follows; from B+ at 120 through R10, a lead 161, lead 160,CLZ, lead 171, lead 170, SID in position No. 4, a lead 206, lead 186,contacts 185, lead 184, 81A in position No. 4, and lead 176 to commonlead 113. The text film face cam is now held in constantly against theclaw arm fol lower by the text film solenoid, and the text film will befed at the rate of reciprocation of the claw arm, which is driven by theconstant-speed radial cam 86 on shaft 75. Feeding may be interrupted ifthere is an aperture or notch N4 in the text film by moving switch 8-14to close its contacts 204 so that, when the aperture registers withcontact brush 207, relay RY1 will be energized to open contacts 185.Otherwise, the feeding is stopped by moving the function switches tosome other position than. No. 4.

The foregoing, detailed description of one embodiment of our inventionis intended to be illustrative and not limiting, the scope of ourinvention being set forth in the appended claims.

We claim: I

1. In a cinematograph, film guide means, film feeding means comprising apivoted claw arm, a first shaft paraltel-w th sai id m a a a being ,ptafly mounted. on said shaft for oscillation transversely of said filmguide and also being slidably mounted on said first shaft forreciprocation parallel to said film guide, a drive shaft arrangedperpendicular to said first shaft, a first cam on said drive shaft forreciprocating said arm parallel with said film guide, a second cam onsaid drive shaft for oscillating said arm perpendicular to said filmguide, said second cam being movable axially on said drive shaft intoand out of engagement with said claw arm, means rigidly fixed on saidfirst shaft for engaging said second cam to move it alternately into andout of engagement with said claw arm as said first shaft is osci1-lated, and electrically operated means operatively connected to saidfirst shaft for oscillating it.

2. In a visual training projector, film guide means for receiving a filmstrip, film feeding mechanism including a film engaging element, meansmounting said element for movement both parallel with said film guideandper; pendicularly thereto, means biasing said element perpen dicularlyoutward from said film guide in a disengaged position, constant speeddriving means operatively associ* ated with said element forreciprocating said element parallel with said film guide through feedingand return strokes at a constant rate, means including anelectromagnetic actuator which, when energized, moves said element intoengagement with a film strip in said guide and holds it there during itsfeeding stroke, an energiz ing circuit for said actuator, a normallyopen switching device in said circuit, means operatively connecting saidswitching device with saidconstant speed driving means to effect theclosing of said circuit at that point during only the feeding stroke ofsaid element, and an electrical'ly operated, variable, time-delay,circuit controlling means normally biased in a circuit closing conditionand rendered operative upon completion of said circuit to effect apredetermined delay in the subsequent completion of said circuit once itis broken. 7

3. In a visual training projector, film guide means for receiving a filmstrip. a normally free-running, intermittent-motion, film feedingmechanism including a movable member for effecting engagement anddisengagement of the mechanism with a film strip in said guide means,constant speed driving means for driving said feeding mechanism at aconstant speed, electrically operated means operatively connected tosaid movable member and which, when energized, effects engagement ofsaid'feeding mechanism with the film strip, an energizing circuit forsaid electrically operated means, a first circuit controlling meansnormally inoperative to complete said circuit, means driven by saidconstant speed driving means and operatively connected to said firstcircuit controlling means to effect completion of said circuit at thatpoint during only a predetermined portion of each cycle of said feedingmechanism, and a second, electrically operated, variable time-delay,circuit controlling means normally biased in a circuit closing conditionand rendered operative upon completion of said circuit to effect apredetermined delay in the subsequent completion of said circuit once itis broken.

4. In a visual training projector, film guide means for receiving a pairof film strips in overlapping'relationship for unison projection, a pairof film strips in said guide, film feeding mechanism comprising a filmengaging element for each film strip, said elements having a normalposition in which they are inoperative to engage the film strips, meansincluding a constant speed shaft for re ciprocating said elementsparallel to said film guide through feeding and return strokes atconstant and similar rates and in phase with respect to their feedingand re turn strokes, means including an electromagnetic actuator foreach of said elements which, when energized, efiects the movement of itsrespective element into engagement with its respective film strip, anenergizing circuit for said actuators, a first circuit controlling meansnormally inoperative to complete said circuit, means driven by saidconstant speed shaft and operativelyconnectedto said 13 a, first circuitcontrolling means for effecting the. operation thereof to complete saidcircuit at that point during only the feeding strokes of said elements,a second, electrically operated, variable time-delay, circuitcontrolling means normally biased in a circuit closing condition andrendered operative upon completion of said circuit to effect apredetermined delay in the subsequent completion thereof once saidcircuit is broken, and switching means for selectively connecting one orthe other of said actuators into said energizing circuit.

5. In a visual training projector, film guide means including aprojection aperture, a film strip in said film guide, film feeding meansincluding a film engaging element having a normally disengaged position,constant speed driving means for reciprocating said element parallel tosaid film strip through feeding and return strokes at a constant rate,means including an electrically operated actuator which, when energized,effects engagement of said element with the film strip, an energizingcircuit for said actuator, a normally open switching device in saidcircuit, means driven by said constant speed means and operativelyconnected to said switching means to effect completion of said circuitat that point during only each feeding stroke of said element,electrically operated, variable time-delay, circuit controlling meansnormally biased in a circuit closing condition and operative upon eachcompletion of said circuit to delay subsequent completion of saidcircuit for a selected number of cycles of said element, said energizingcircuit further including push-button starting means and relay means forholding the circuit across said push-button when it is released, and afilm position sensitive interrupter switch for breaking said holdingcircuit when a predetermined number of frames of the film strip havebeen fed through the projection aperture. a

6. In a visual training projector, film guide means arranged to guide apair of film strips in overlapping relationship for unison projection, apair of film strips in said guide, film feeding mechanism including afilm engaging element for each of said film strips, said elements havinga normally disengaged position, means including a constant speed shaftfor reciprocating said elements parallel to said film guide throughfeeding and return strokes at constant and similar rates, meansincluding an electromagnetic actuator for each of said elements which,when energized, effects engagement of its respective element with a filmstrip, an energizing circuit for said actuators, a normally openswitching device in said circuit, means driven by said constant speedshaft and operatively connected to said switching device to completesaid circuit at that point during the feeding stroke only of saidelements, an electrically operated, variable time-delay, circuitcontrolling means normally biased in a circuit closing condition andrendered operative upon completion of said circuit to effect apredetermined delay in the subsequent completion thereof once it isbroken, manual selective switching means for connecting either of saidactuators into said energizing circuit thereby to feed one or the otherof said film strips, and switching means sensitive to a predeterminedposition of the film strip being fed to connect both of said actuatorsinto said energizing circuit thereby to feed both film stripssimultaneously.

7. In a device of the kind described, film feeding mechanism including anormally disengagedfilm engaging element, constant speed driving meansoperatively connected to said film engaging element for reciprocating itthrough feeding and return strokes at a constant rate, means includingan electrically operated actuator which, when energized, effectsengagement of said element with a film strip, a circuit for energizingsaid actuator during each feeding stroke of said element or during anyintermittent occurrence thereof, a normally open switch in said circuit,means operatively connecting said switch with said constant speeddriving means f r c s g ai switch during ssent w t r 14 each feedingstroke of said' element, said circuit further including the plate tocathode circuit of a grid-controlled, electron discharge tube, meansnormally biasing the tube grid to cut ofi tube conduction, startingcircuit means including a manual switch for altering the bias on thetube grid to effect tube conduction, means including an electricallyoperated switch rendered operative each time said energizing circuit iscompleted to apply a strong, negative, cut-off pulse to the tube grid,capacitor means for retaining this strong negative tube bias, circuitconnections with the tube grid including a variable resistor forvariably timing the leak-off rate of the strong negative grid bias,means for applying substantially uniform, positive, trigger pulses tothe tube grid at the start of each feeding stroke of said elementincluding a switching device operatively connected to said constantspeed driving means, thereby to re-establish tube conduction coincidentwith the start of a feeding stroke, and holding means in said energizingcircuit rendered operative upon completion of said circuit to maintainthe continuity thereof after the strong negative bias is applied to thetube grid and until said circuit is broken at another point.

8. In a device of the kind described, film feeding mechanism including anormally disengaged film engaging element, constant speed driving meansfor reciprocating said element through feeding and return strokes at aconstant rate, means including an electrically operated actuator which,when energized, effects and maintains engagement of said element with afilm strip, a circuit for energizing said actuator, a normally openswitch in said circuit, means driven by said constant speed drivingmeans and operatively associated with said switch for effecting theclosure thereof during each feeding stroke of said element, said circuitfurther including the cathode to plate circuit of a grid-controlled,gas-filled, electron discharge tube normally biased in a non-conductingcondition, starting circuit means including a manual switch for biasingthe tube grid so as to effect tube conduction thereby to effect thecontinuity of said energizing circuit through said tube, means includingan electrically operated switch rendered operative upon each completionof said energizing circuit to apply a strong negative cut-off pulse tothe tube grid, capacitor means for retaining the strong negative gridbias, circuit means including a variable resistor for timing theleak-off of the strong negative grid bias, and means for applyingsubstantially uniform, positive, trigger pulses to the tube grid at thestart of each feeding stroke of said clement, whereby the instant ofrecurrence of a grid bias which will fire said tube and re-establishconduction therethrough coincides with the start of a feeding stroke ofsaid element, and said last-mentioned means including switching meansoperatively connected to said constant speed driving means.

9. In a visual training projector, means for guiding a pair of filmstrips in parallel, closely spaced, overlapping relationship forsimultaneous projection comprising a fiat guide strip having alongitudinal guide channel formed in both sides thereof, a centrallylocated projection aperture in said strip, an elongated film gate oneach side of said strip, said film gates each having a portion overlyingsaid aperture and a portion extending along said strip from saidaperture in a direction opposite that of the other, a pair oflongitudinal slots in said guide strip one on each side of said apertureand each coextending with the extending portion of one of said filmgates, film feeding mechanism operative to feed a pair of film strips inopposite directions through said guide means each in a direction toapproach said aperture from the side thereof opposite that of therespective extending film gate portion, said film feeding mechanismincluding a pair of reciprocating film engaging members one on each sideof said guide strip and each having an element perpendicular to saidguide strip and arranged to enter perforations in a film strip and aslot in said guide strip and to. pass thmugh the filmgnq the guidestrip.

Gauriat Ap1'. 27, 1926 Uher Oct. 2, 1934 Blum Oct. 26, 1937 KelloggSept. 19, 1939 10 I Guerciq ...j' D 0. 1, 11942 Masterson Mar. 20,1945Dubg' Mar. 11, 1952 Henschke et al Mar. 25, 1952 Davidson et' a1. J an.24, 1953 Dockum Jan. 17, 1956 Stoyan0fi Jan. 1, 1957 Seidler June 11,1957 Kingston Aug. 13, 1957

